Hellspark Elemental and Spark Elemental seem better than Ball Lightning... but that's just my opinion. If you splash , you have access to Lightning Helix, Boros Charm, Path to Exile, and Wild Nacatl. BTW if Blood Moon really that big of a problem, just run 1 of Forest or run Molten Rain instead ... also why is Pyrite Spellbomb in the sideboard?

Hellspark Elemental and Spark Elemental are horrible top draws late game, whereas Ball Lightning is not.

I've toyed with a splash and have not due to the potency of Blood Moon that I often board in, also the life loss affects the mirror match as well as other Aggro decks. I still have considered it, and may if my meta shifts.

Pyrite Spellbomb is for Kor Firewalker, Etched Champion, and other Protection from Red stuff. It's never a dead card as I can burn to the dome as well.

I think you are overestimating the potential of Ball Lightning. You would be better suited to running 2 Grim Lavamancers. He provides the reach the deck is lacking and allows you to eke out the last few point of damage. Ball Lightning costs too much for the effect it has.

Maybe, but the fun and surprise factor with Ball Lightning is awesome. I really have to play smart with it, though. He's best when the opponent is tapped out and can certainly end the game, as well as serve as a pseudo removal spell.